In the Class::DBI POD, under "DEFINING SQL STATEMENTS", there's a section about Class::DBI::AbstractSearch .. the example given is:

               my @music = Music::CD->search_where(
                       artist => [ 'Ozzy', 'Kelly' ],
                       status => { '!=', 'outdated' },
               );
[download]

That would do the search based on sql that looked like artist IN ('Ozzy', 'Kelly') AND status != 'outdated' (note that exact sql depends on config; e.g. it could be OR instead of AND if desired)